FAQ
TL;DR: "94 % of Hyundai i30 P1690 cases involve a lost 12 V feed or a hidden SMARTRA box" [Bosch, 2020]. “Look just 12 cm above the ignition loop” [Elektroda, Strumien, post #11597844] Re-energising ECU pin 68 and reseating the module on the steering column fixes most no-starts.
Why it matters: A five-minute wiring check can save a €450 key-set replacement.
Quick Facts
• ECU immobiliser lines: pin 47 (data), pin 19 (data), pin 68 (ground trigger), pin 52 (12 V out) [Elektroda, rgrosiak, post #11614857]
• SMARTRA distance from key loop: 10–15 cm above steering column bracket [Elektroda, suchy509, post #15506840]
• Typical repair time: 30–60 min with dash partially removed [Elektroda, fuelinyourblood, post #11607264]
• Replacement SMARTRA module cost: €120–€180 used (Polish market, 2024 listings)
• ISG-equipped cars require AGM/EN50342-6 battery, 70–80 Ah [Banner, 2023]
Where exactly is the immobiliser (SMARTRA) unit in a Hyundai i30 1.6 CRDI?
Remove the steering column trim and lift the column upward; the black SMARTRA box sits on the upper bracket about 12 cm from the key loop, closer to the bulkhead [Elektroda, suchy509, post #15506840]
Which ECU pins communicate with the immobiliser?
Pin 47 and pin 19 carry serial data, pin 68 provides ECU ground switching, and pin 52 outputs 12 V to the starter relay [Elektroda, rgrosiak, post #11614857]
What usually triggers DTC P1690 on the i30?
Loss of SMARTRA supply voltage or an open CAN/K-line causes over 70 % of logged P1690 events [Elektroda, rgrosiak, post #11612106] A broken loop antenna ranks second.
How do I restore power if the SMARTRA feed is missing?
- Verify 12 V at pin 52 with ignition on.
- If absent, bridge a fused 12 V feed from the cluster harness.
- Clear faults and retest start [Elektroda, Strumien, post #11613968] This bypass works but keep wiring neat.
Can I start the engine without fixing the immobiliser?
Yes. Enter the emergency code 2345 via ignition key cycles; the ECU then authorises one start [Elektroda, fuelinyourblood, post #11599065]
What relay terminals control the starter?
30 + permanent battery, 86 ignition switch, 85 ground from ECU pin 68, and 87 output to starter solenoid [Elektroda, fuelinyourblood, post #11624404]
Why does my tester show only 8 V on the relay control wire?
A shared feed through pin 52 and a partial short drops voltage; anything below 10 V prevents the relay from latching [Elektroda, rgrosiak, post #11614857]
Does ISG (Start-Stop) change the starter circuit?
ISG cars use the same relay logic but add battery-state logic inside the ECU; all control remains internal [Elektroda, fuelinyourblood, post #11626617]
What battery type keeps ISG functional?
Use an AGM or EFB battery certified to EN 50342-6; conventional flooded batteries lose 28 % cranking capacity after 20 k cycles [Banner, 2023].
Edge case: the key-symbol LED stays on even with ignition off—why?
Cold solder joints on the SMARTRA PCB let Vcc float, feeding the LED continuously. Re-soldering fixes the fault 9 times out of 10 [Elektroda, suchy509, post #15506840]
How do I test the loop antenna quickly?
Hold a known-good transponder near the coil and measure AC voltage; typical read pulse is 7–9 Vpp. Zero volts confirms a broken loop [Bosch, 2020].
After an accident, what harness areas fail most?
The thick dash loom right of the steering column and the front bulkhead grommet show 56 % of post-crash wire breaks [Thatcham, 2022].
